1. Field of the Invention
The present invention relates to a method of manufacturing an optical waveguide device which has found wide use in a variety of electric and electronic technologies using optics such as optical communications, optical information processing and the like.
2. Description of the Related Art
In general, an optical waveguide device achieves optical coupling by causing an optical waveguide to propagate a light beam emitted from a light-emitting element or causing a light-receiving element to receive a light beam propagated by the optical waveguide. For the coupling, it is important to set their optical axes coaxially, and high positioning accuracy is required. Recently, an optical waveguide device (including an optical module) having a receptacle structure capable of easily accomplishing such positioning has been proposed and used widely for optical communications and the like (see Japanese Patent Application Laid-Open No. 2006-154553) (Patent Document 1).
As shown in FIG. 6, for example, an optical module described in Patent Document 1 includes a board 2 with an optical element 1 such as a planar light-emitting element mounted thereon, and a receptacle capable of positioning a flexible optical waveguide 3 so that the flexible optical waveguide 3 lies on the same optical axis as the above-mentioned optical element 1.
The above-mentioned receptacle 4 is composed of a first receptacle part 6 provided with a lower groove 5 serving as a guide way for the positioning of the flexible optical waveguide 3, and a second receptacle part 8 provided with an upper groove 7 similarly serving as a guide way. The first receptacle part 6 and the second receptacle part 8 are assembled together into a single unit by fitting guide pins 9 and 10 mounted upright on the upper surface of the board 2 into guide holes 11 and 12 provided in the lower surfaces of the above-mentioned first receptacle part 6 and second receptacle part 8, respectively.
However, the formation of the receptacle structure of this optical module requires the step of producing the two parts, i.e. the first receptacle part 6 and the second receptacle part 8, and the step of assembling these parts on the board 2, presents the problem of requiring cumbersome and complicated labor. Additionally, since the positioning of the optical element 1 and the flexible optical waveguide 3 is accomplished by the above-mentioned assembled receptacle structure, the accumulation of the machining accuracy and assembly accuracy of the plurality of members influences the entire accuracy. Thus, there arises another problem in that it is not easy to adjust the entire accuracy.
To provide the plurality of members constituting the receptacle structure with high dimensional accuracy, it is necessary to mold a resin containing an expensive solid filler (having a size ranging from several to tens of microns, and monodisperse) in high concentration with a die manufactured with high dimensional accuracy. This presents still another problem in requiring not only high material costs but also high running costs of the die because the die is prone to be damaged due to the above-mentioned solid filler.